Base params in Json Store

Hi!
I'm trying the Ext Designer and I want to create something I've already done with a simple editor, just to see how it goes...
I want to create a Json Store but I have to post one or two variables to the php page that will return the data... I don' t see any property like "baseParams" or something like this...

We will add to our list the addition of baseParams to all store types for the next release. In the meantime, you can work around this issue by providing the data as query string parameters to your url config. Thanks.